Hi,
The plugin and documentation you refer to belong to the old v5 version.
In the current version you don't need to install a plugin. The autologin feature is present in the current version, you only need to enable it in the Acymailing config. Based on your image it looks like you have enabled the feauture and it should work.
To provide you with the best assistance possible, I kindly request that you submit a support ticket through our website at https://www.acymailing.com/support/. Our team will be able to efficiently and effectively provide you with the assistance you need.
Please note that our ticket support is exclusively available for our customers with an active Essential or Enterprise license. If your license has expired or you are using the Starter version, we kindly invite you to renew or upgrade your license prior to opening your support ticket.